In the 1914 case Hendrick v. State of Maryland, the United States Supreme Court upheld a Maryland law requiring all motor vehicles to be registered with the state and display license plates. The appellant, Roscoe B. Hendrick, argued that this requirement violated his constitutional right to travel freely between states without interference from individual states. However, the court ruled in favor of Maryland stating that while citizens have a right to move across state lines freely, they do not have an absolute right to use any particular method of transportation or bring their property into another state without restriction or regulation by that state for public safety purposes. Therefore, it was within Maryland's power as a sovereign entity under its police powers to regulate traffic on its roads and require vehicle registration and licensing.

In the dissenting opinion for Hendrick v. State of Maryland, Justice McKenna expressed his disagreement with the majority's decision to uphold a state law requiring out-of-state drivers to obtain a license and pay a fee before operating their vehicles in Maryland. He argued that this law violated the Commerce Clause of the Constitution by placing an undue burden on interstate commerce. In his view, driving was not merely a local activity but also involved crossing state lines for commercial purposes, making it part of interstate commerce which should be regulated by Congress rather than individual states. Furthermore, he contended that such laws could lead to retaliatory measures from other states and create confusion due to differing regulations across states. Therefore, he believed that uniform national regulation was necessary in this area.